Cannabidiol is a cannabinoid found in Cannabis and was first described as a solid in the chemical literature by Roger Adams in the Journal of the American Chemical Society, 1940, V62, P2194-6 as having a melting point of 66° C.-67° C. In 1977, it was isolated as a solid by crystallization from pentane by Jones, Peter G: Acta Cryst. (1977) B33, P3211-3214 and was reported to have a melting point of 66° C.-67° C. as well. Cannabidiol is also isolated as an oil directly from the hemp plant and is converted to a white crystalline solid, m.p. 64° C.-66° C. by the process provided by Flockhart, et.al.: US2006/0167283, which also lists a literature value of the Cannabidiol melting point of 66° C.-67° C.
An orally-administered liquid containing Cannabidiol has received orphan drug status in the US, for the treatment of Dravet Syndrome (a form of epilepsy), under the (GW Pharma) brand name Epidolex (Wilner, A N; 25 Mar. 2014, “Marijuana for Epilepsy: Weighing the Evidence” Medscape Neurology). Cannabidiol is also a component of Namiximols (USAN, trade name Sativex), which is an aerosolized mist for an oral administration containing a near 1:1 ratio of Cannabidiol and THC. This drug was approved by Canadian authorities in 2005 to alleviate pain associated with multiple sclerosis. Cannabidiol has been suggested as an agent for the treatment of epilepsy as set forth in U.S. Pat. No. 9,125,859, the contents of which are incorporated herein by reference. It has also been proposed for use as an anti-inflammatory reagent WO 9952524 A1 19991021 and for treatment of cancer (WO 2013038157 A1). Cannabidiol is currently undergoing various clinical trials.
The new form of crystalline Cannabidiol described and claimed herein differs from the m.p. 66° C.-67° C. form, for example, in its XRPD pattern and by having a lower melting point. This new polymorph could be more advantageous in one or more respects compared to the other form, for example, in terms of easier, quicker and more extensive dissolution into solvents and more rapid bioavailability commensurate with the lower melting temperature, equating to a less thermodynamically stable and hence more soluble polymorph compared with the other form.